Let's take a closer look at what are the main contents of motor classification?
According to the type of working power supply, it can be classified into DC motors and AC motors.
DC motor: Its structure should consist of stator and rotor. The stationary part of the DC motor is called the stator. The main function of the stator is to generate a magnetic field, which consists of a base, a main magnetic pole, a commutation pole, an end cover, a bearing and a brush device. During operation, the rotating part is called the rotor. Its main function is to generate electromagnetic torque and induced electromotive force. It is the hub of the energy conversion of the DC motor, so it is usually called the armature. device and fan.
AC motor: AC motor is a very broad category, and there are many types of motors themselves. The AC motor itself can be divided into low speed and high speed. Low-speed motors can be called low-speed motors, AC low-speed motors, high-speed motors can be called high-speed motors, high-speed motors, AC high-speed motors, and high-speed motors can be called electric spindles, high-speed electric spindles, etc.
According to the structure and working principle, it can be divided into DC motor, asynchronous motor and synchronous motor.
A DC motor is a variable frequency motor: it changes the speed of the motor by changing the frequency of the input three-phase alternating current, and the frequency conversion is used for speed regulation. The frequency conversion motor adopts the AC speed regulation method of "special frequency conversion induction motor and frequency converter", which greatly improves the degree of mechanical automation and production efficiency, miniaturizes the equipment, and increases the comfort. At present, it is replacing the traditional mechanical speed regulation and DC speed regulation scheme.
Asynchronous motor: The basic feature of asynchronous motor is that the rotor winding does not need to be connected to other power sources, and its stator current is directly taken from the AC power system. Compared with other motors, asynchronous motors have the advantages of simple structure, convenient manufacture, use and maintenance, high reliability, light weight and low cost.
Synchronous motor: When the synchronous motor is working, the three-phase symmetrical current flows into the three-phase windings of the stator, and the DC current flows into the excitation winding of the rotor. When three-phase alternating current is applied to the three-phase symmetrical windings of the stator, a rotating magnetic field is generated in the air gap. When a DC current acts on the rotor field winding, a static magnetic field of constant polarity is generated.
According to the starting and running mode, it can be divided into capacitor-started single-phase asynchronous motor, capacitor-run single-phase asynchronous motor, and split-phase single-phase asynchronous motor.
Capacitor-started single-phase asynchronous motors: Starting capacitors refer to AC electrolytic capacitors or polypropylene and polyester capacitors used to start single-phase asynchronous motors. Induction motors have two windings, the starting winding and the running winding. The two windings are spatially separated by 90 degrees. A bulk capacitor is connected in series with the start winding. When the running winding and the starting winding pass single-phase alternating current, the current in the starting winding is 90 degrees ahead of the current in the running winding due to the action of the capacitor, and reaches the maximum value first.
Capacitor-run single-phase asynchronous motors: A single-phase capacitor starter motor is a capacitor in series with the auxiliary winding of the motor. After the motor is started, the auxiliary winding is disconnected and does not participate in the operation of the motor. A single-phase capacitor running motor refers to the auxiliary winding and the working capacitor in series with it. Whether it is the starting process or the running process of the motor, it is always connected to the power supply and participates in the operation of the motor.
Split-phase single-phase asynchronous motor: A two-phase asynchronous motor powered by a single-phase AC power supply after phase splitting through capacitors or resistors. Most single-phase asynchronous motors are essentially split-phase asynchronous motors. Since the single-phase current generates a pulsed magnetic field in the air gap of the motor when the single-phase current passes through the armature winding, the rotor winding of the static asynchronous motor can only function as a transformer and cannot generate torque, so the single-phase asynchronous motor cannot self-start.
